Foundry mold practice



J 1950 w. E. REHKLAU I 2,510,417

FOUNDRY MOLD PRACTICE Filed April 28, 1948 34 I [III/III) h a.

Patented June 6, 1950 FQUNDR'Y Maximum-Elfin I waiters:itshknmg'rqledo,ohm,- 'ApplicationApril 28; 1848;:8eriatilfifaffifl'ti- This invention. relates..to...the romotion. of 1!- nciencyrinmoidingpractices. g,

This; invent'om has; utility in theyntold-ing of cores... and-more particularly. has do .witttthe handling; otcore boxesdt ring thecharging theree otby. air blasts of thesmolding sand or granular material to be'shaped .intoa a. formifortacore obiect toabewthereafter baked to}; impart, sufiicient rig-iditywtheretoz that itmay be assembled as: a

core in. a-molda: The generalcharactenofithe core box may be. ofaluminunrcasting or otiron, wood, or other material...- Frequently,.-eyerr when gen erally' -of,:.aluminum,, there; may. be patches. .or special portions of-,other. metal. ashrass. iron or solder. v 1

Consideringfthacorebox of two major sections or parts, there is a lower section or half, and a complementaryupper section or half. Upon assembly; thepurpose isforfully enclosinga chamber for the core to be formed. Accordingly, the respective sections...are partible along the chamber at smooth"surfaces'adapted to abut for snug registry. Depending upon Whether the core chamber -=be flat -or-devious, the -parting -reg=ion may bear plane,- or planes-connected by more or less abrupt regions or arcs" of concave or: convex form: 'In-=the--carrying 'out' "of- "the invention, bounds at the parting-in one or the sections, as the-upper section, may havea dovetail seat or channel-to carry a compressible sealing element of continuity: Furthermore the blastway and direct impingementare lined or -f aced with rubber characteristic material not subject to disintegration. Referring tothe drawings:

' Fig.1 is an outline of-a four-cylinder-exhaust manifoldcorey I g 7 Fig.2 is a side elevation of the -manifolci core of--Fig.=1;- v

3 isagraph of'sealing-element course portion in side elevation for-the coreof Fig- .-'l;-

Fig. 4 is a graphof'sealing element coursegortion in plan lookingdown-on *a' turned over top section for the core of Fig. 1;

Fig. 5 is a section on the line V-V, Fig. 1, showing blast tube lining and facing with sealing features;

Fig. 6 is a larger scale showing of the sealing element in section.

Fig. '7 is a section thru the groove or holding channel, as in a convex region VII-VII, or a concave region VII'-VII' Fig. 3; and

Fig. 8 shows special adaptation of the elastic strip to avoid puckering at abrupt direction changes in the channel or way, as in a region VII[-VIII and a region VHF-VIII Fig. 3, as

' '1; Claini. (01.22-13) well for regions VIII-'1 Fig.4.; I

CQntounoutIineL. 4, 5 (Fig.-. 15;, or, a foun ylinder; internal combustion motor; exhaust maniioldcore, isshownaaforapatternnrmold havinggranular materialgor :sand blastjcharging orts 6.. and ..distri buted air-escape .or. seepage screen .Ior. latticed ports I. 'toretain thacore nia- {serial grains... The ports. 1- aresalocated thatthe bla\.vr.i-.in sand grains.. m ay belodged-uniformw thruont the; core; moldin completingitsgformav tion. Thasports..1. fdr..a.ir' esoapaare shdwnfinr indicated as; from uppencor mold-seqtionfigwith similar .jports t -in a ,eomplementary lower core moldseotionl The mold section 8, :hasthereih a. core mold-.channehl I. adapted to re ister with atcomplementary core .moldchannel (2 in the section l'u 'llhesectiont has. parting. facesmooth region. l3. vextemling;away from. opnosite. sides. of the channel... U, Adapted for, tight-.nttingregister therewith, as.;abutti:ng;; thereon, the. section [0 has parting face." 1.4:. Outline. portionsl f. arefm? cylinders .intermediate.the portions .l.

.- Underthe inventionhereimblastways or ducts IS KFigQ 5).;asseats-have aimin 16'. with an outer meomnletely countersunk it flan e por ion l1.

'adaptedior sand .blast nozzletnon-leak insertion.

The discharged granular A material is. impin ed upon core m ld wall pn site the. entrance. or

delivery 18. .from i the llininge l Adhesive or cement I 9... anchors. .a. faoedisk'. at with adisk 0 Plate lltremovably locked by. a screw 22 in aselat 2.3.Zdirectly iniront'of, the port i8.

I n. he. facels-oithe ti p ced mor or lessjunifo'jrmly away fromthe.coremoldflcham nel iil, l, endless way or bounding groove 24, say of normal dovetailf"contour=in cross-section, is provided; v The groove 2-4'-'is an endless seat -i'n which is locateda yieldable elastic strip 25 having dove-tail I underout lcomplementary seat portion'sits The face orexpose'd portion of'the strip 2 5 has 'a *convexbead or rib 21-," back of -which in the groove 24 the strip has a concave arc thinned portion 28. There is thereby promoted the give factor achieved for snugly forcing the rib 21 in uniformly effective contacting relation thruout with the face M of the abutting section In with the section 8 of the core mold or box.

Foundry practice in the handling of granular material or molding sand for core boxes, has special ingredients or substances, as resin or oil incorporated therewith, to coact as a bonding agent for holding the grains together for transfer to the heating or baking stage, as well as to retain sufficiently rigid form thereafter to respond to in as a potent agent in contributing to core box upkeep in sealing against abrasion, as well as coact in speeding up foundry operations. cordingly, the liner IS, with its flange H, the disk and the strip are of a selected elastic yieldable plastic, usually a synthetic substance, such as neoprene. I

Deviations from fiat plane direction for the abutting faces [3, [4, are taken into account for the effective sand blast sealing between the core box sections. At more or less abrupt angles or "corners 29, 30, 3| (Fig. 3),, graph, the dovetail groove 24 may be fared out thereinto to avoid sharp cutting edges, whether acute, right angles, or obtuse, and of the degree therefor. However, for arcuate paths, whether convex region 32, or concave region 33 (Fig. 3), the cutting tool for forming the groove 24 does not readily holdto the seat cross-section as such curved regions may be of radius say 1" or less, on the basis that the groove 24 may be in the range of wide at its root, and say /e" to 1%" deep with the opening or throat say 1%". to A" wide.' Accordingly to meet this special arc condition a groove portion 34 (Fig. 7) may boot a width slightly wider than the throat of the normal dovetail thereto, but not so wide as the root. However the rectangular cross-section groove 34 may be slightly deeper than the groove 24. The stretch or elasticity of the strip 25 is such as readily to conform to the special directions, not only as up and down, but as sinuous or more or less tortuous in the plane laterally from the core channel ll. Corners 35, 36 (Fig. 4) graph, may' 5 34. From this it follows that there is to some extent an availing of the elasticity for stretching the strip 25 into its bounding seat for thechannel II. There is normally ample frictional holding so to retain the strip, but as occasion may arise, the strip 25 may be readily pulled free therefrom for later re-use or replacement.

What is claimed and it is desired to secure by Letters Patent is:

A mold box first section providing a channel way portion forming spacing means between coplanar faces extending away from the Way portion, a complementary second section having a channel way portion adapted to register with the channel way portion of the first section to form a cross-section completed passage of lineal extent for a duct in the assembled mold box, the

second section having faces abutting the coplanar faces of the first section in said assembly inproviding a peripherally complete bounding wall for the passage at the cross-section, laterally spaced from each other by said passage there being a pair of dove-tail grooves in one of the Y. sections, said grooves having in cross-section configuration a straight bottom between a pair of corners, and compressible filler strip means for the respective grooves, said strip means being configured in cross-section with diverging corner portions to register in the dove-tail groove corners with a concave face portion providing centrally along said groove bottom a clearance width way, said strip means having outwardly from the concave face portion a narrower convex rib portion of less width than the clearance width way of the opposite side of the strip means, said rib portion coacting upon the assembly of the first section with the second section to squeeze the rib portion toward the coplanar abutting faces into bridging relation and further distort the strip means in reducing the concave clearance of the strip means relatively to the dove-tail groove therefor.

WALTER E. REHKLAU.

REFERENCES CITED The following references are of record inthe file of this patent:

UNITED STATES PATENTS Number Name Date 593,267 Adams Nov. 9,1897 831,603 Davis Sept. 25, 1906 875,228 Witham Dec. 31, 1907 1,463,360 Foote July 31, 1923 1,514,192 Bausman Nov. 4, 1924 1,560,097 Petersen Nov. 3, 1925 1,594,598 Campbell Aug. 3, 1926 1,761,522 Elsey June 3, 1930 1,950,432 Carothers Mar. 13, 1934 2,038,249 Stoody Apr. 21, 1936 2,106,817 Soule Feb. 1, 1938 2,157,983 Glougie May 9, 1939 2,203,123 Astle June 4, 1940 2,208,620 Biasch July 23, 1940 2,376,593 Hellen May 2,1945 2,419,322 Matheny Apr. 22, 1947 2,423,341 Peterson July 1, 1947 2,439,923 Clark Apr. 20, 1948 2,443,959 Merrill June 22, 1948 

